Antihypertensive Mechanisms of Minocycline in Resistant Hypertension

Inclusion Criteria: * Age ≥18 years * Uncontrolled TRH, defined as uncontrolled blood pressure (mean 24-hour ambulatory systolic BP ≥125 mm Hg or diastolic BP ≥80 mm Hg) while being adherent to a stable (no changes in ≥14 days prior) antihypertensive regimen of 3 or more drugs, including an adequately dosed diuretic or unable to tolerate a diuretic. * The participant agrees to have all study procedures performed Exclusion Criteria: * Known hypersensitivity or contraindication to minocycline or other tetracyclines * Recent (≤3 months prior), ongoing, or expected use of oral antibiotics * Estimated glomerular filtration rate (eGFR) of \<45mL/min/1.73m2, using the MDRD equation * Known secondary hypertension * History of hypertensive crisis, defined as any in-patient hospitalizations for hypertensive crisis/emergency within the past year * History of orthostatic hypotension, defined as two or more episode(s) of orthostatic hypotension (reduction of SBP of \>20 mm Hg or DBP of \>10 mm Hg within 3 minutes of standing) in the past year * History of myocardial infarction, unstable angina, syncope, or cerebrovascular accident in prior 6 months * Evidence of alcoholism or drug abuse * Severe comorbid conditions (i.e., neoplasms or HIV positive or AIDS) * Current pregnancy or anticipated pregnancy during the study.